What is the blue light from our screens really doing to our eyes?

We’ve known for a while that excessive screen time is not good for your sleep schedule, but the latest findings are overwhelmingly gloomy – and extend well beyond insomnia.

An eye doctor says he’s recently seen a few 35-year-old patients whose lenses, which are typically clear all the way up until around age 40, are so cloudy they resemble 75-year-olds’. A sleep doctor says kids as young as toddlers are suffering from chronic insomnia, which in turn affects their behavior and performance at school and daycare. A scientist finds that women who work night shifts are twice as likely to develop breast cancer than those who sleep at night.

What do all these anecdotes have in common? Nighttime exposure to the blue light emanating from our screens.

You’ve probably heard the hype these past few years: being in the presence of light at night disrupts the body’s natural circadian rhythms by suppressing the production of melatonin, a sleep hormone. But melatonin does far more than help us get sleepy – it’s also an antioxidant that appears to play a pivotal role in slowing the progression of cancer and other diseases.

“I’ve been spending a lot of the past 20 years worrying about it,” said Dr. Richard Hansler, who clocked in 42 years at GE Lighting developing “all kinds of bright, beautiful lights” before his move to John Carroll University in Ohio, where he studied the effects of light at night on our health. It was the mid 1990s, and at that point, he said, his concern wasn’t widely shared.